Timer-1
Nathan writes

If you’ve ever seen a boxing match, you know that two people ‘box’ each other in rounds. To train, boxers use a timer on the same time base as a fight so that their bodies get used to 3 minutes of boxing and 1 minute of rest, during a bout.

My goal was to re-create the timers found in our local Front Range Boxing Academy. At the gym, a common boxing timer is used and the bulbs keep burning out. That is unacceptable in this day in age with LEDs lasting at least 30 times longer than regular incandescent bulbs. These common boxing timers are also expensive ($99)!

Some days it is painful being an engineer. Looking at this hunk of metal, I know inside there is just a microcontroller, a loud speaker, a couple switches, some lights, and a whole lot of empty space… This is a pretty straight forward project! Forgive me, but I tend to use a lot of stuff around the office that is readily available. And because this was meant to be an example project, I used all through-hole components.